%0 Journal Article
%T Geochemistry and petrography of Early Paleozoic Yusupuleke Tagh rapakivi-textured granite complex, South Altyn: An example for magma mixing<br>阿尔金造山带南缘岩浆混合作用:玉苏普阿勒克塔格岩体岩石学和地球化学证据
%A WANG Chao
%A LIU Liang
%A ZHANG AnD
%A YANG WenQiang
%A CAO YuTing
%A <br>王超
%A 刘良
%A 张安达
%A 杨文强
%A 曹玉亭
%J 岩石学报
%D 2008
%I 
%X The calc-alkaline granites of the Yusupuleke Tagh batholiths are associated with abundant mafic magmatic enclaves (MME) and aplite dikes. The granitc complex exhibits excellent evidence for magma mixing and mingling, such as the K-feldspar megacrysts in MME, long prisms of apatite, rapakivi feldspars (plagioclase-mantled K-feldspars), oikocrysts of quarts and feldspar-sphene ocelli. These suggest that mixing process of granitic and more mafic magmas induce the formation of the rapakivi texture. Textural evidence of the rapakivi magmas is better preserved in aplite than in the more deep-seated rapakivi granites formed by slow cooling, that indicate the decompression during crystallization of the magmas may promote the production of the mantled alkali feldspar megacrysts. Geochemical, there are linear arrays in binary diagrams. MME and host granitoids are considered cogenetic, and are hybrid rocks that were produced by the mixing of two components in different proportions. The granites are characterized by high Ga/Al, K2O/Na2O, Fe/Mg and low CaO, and showing A-type granite signatures but the aplites are peraluminous, high Na2O, CaO, similar to more felsic, fractionated A-type granites. Chemical data suggest that the MME originated from the enriched mantle melts, whereas the felsic component was produced by partial melting of preexisting crustal materials. Deep-seated interactions between felsic and mafic magmas were responsible for the common characteristics of both magma suites. The chemical evolution of post-orogenic plutnism indicates mantle-crust interactions at decreasing depths in an actively extending orogen. The distinct composition and rapakivi-texture of the granitoids reflects two stages of hybridization and emplacement at the end of an orogenic cycle.
%K Rapakivi texture
%K Disequilibrium texture
%K Mafic microgranular enclaves
%K Magma mixing
%K Yusupuleke Tagh granite complex
%K Altyn<br>环斑结构
%K 不平衡结构
%K 暗色包体
%K 岩浆混合作用
%K 玉苏普阿勒克塔格岩体
%K 阿尔金
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=E9E932DD2950BC0E3764E4B9D16ADF69&yid=67289AFF6305E306&vid=B91E8C6D6FE990DB&iid=59906B3B2830C2C5&sid=B28E8FF0A5EC71B0&eid=FD538B8D3B94D5D7&journal_id=1000-0569&journal_name=岩石学报&referenced_num=3&reference_num=57